Cooking Some Trigger Foods May Help Prevent Anaphylaxis

New research about food allergies that can trigger severe reactions such as anaphylaxis has shown that cooking some foods can prevent attacks and help build tolerance.

One study, which recently appeared in the Annals of Allergy, Asthma & Immunology, found that nearly 75% of children who reported allergies to cow’s milk can tolerate significant quantities of it in baked foods.

Another study, which was discussed in the letters section of The Journal of Allergy and Clinical Immunology, found not only did boiled peanuts produce little to no reaction in 4 children with peanut allergies, but also that they could provide the same benefit as conventional oral immunotherapy with minimal risk.

The first study came from Australia and Britain, where researchers performed oral food challenges on 70 children who had been diagnosed with cow’s milk allergies. Children ate increasing amounts of baked muffin until they had either consumed a full muffin or suffered a reaction.

Of that group, 51 (73%) suffered no reaction of any kind and got the green light to incorporate baked cow’s milk into their diets. The remaining 19 (27%) reacted to the baked milk, often quite severely, and 4 of the children developed anaphylaxis, requiring intramuscular injection.

The researchers then looked for factors that differentiated children who did and did not react to the baked milk and found several significant associations. Asthma, particularly asthma requiring preventer therapy, correlated with greater risk, as did IgE-mediated clinical reactions to more than 3 food groups and a history of anaphylaxis from cow’s milk.

The researchers advised caution in exposing any child with a cow’s milk allergy to baked cow’s milk, even in the absence of additional risk factors. “Given the potential for anaphylaxis, an oral food challenge to baked cow’s milk should be done under medical supervision in those children with allergies who have been strictly avoiding all cow’s milk,” they wrote.

On the other hand, the researchers concluded that enough high-risk children tolerate baked cow’s milk to justify challenges for them — with the proper precautions. “Risk factors,” they noted, “do not represent contradictions to a baked cow’s milk challenge but may allow for risk stratification of challenges.”

The news about boiled peanuts came from ongoing work in London, where researchers have been performing oral challenges on children with diagnosed peanut allergies.

Lab research has already shown boiling peanuts reduces their ability to trigger IgE reactions in the Petri dish, but these are tests are among the first to find that boiled peanuts trigger fewer reactions than raw or roasted peanuts in human subjects with documented allergies.

Boiling, the researchers say, results in the loss of allergenic proteins, particularly Ara h 2, 6, and 7, from peanut seeds.

Subjects initially received peanuts that had been boiled for several hours, but researchers reduced the cooking time every few weeks until symptoms developed. All the subjects developed increased tolerance; one was able to begin eating raw or roasted nuts with no reaction.

“We have demonstrated that the in vitro reactivity correlates with in vivo clinical reactivity, something that had not previously been reported,” the researchers wrote.

“While we cannot exclude the possibility that some person’s allergy may be tolerant to boiled peanut de novo, on the basis of this data we believe that… tolerance to boiled peanut was induced through oral desensitization.”